Pump bearing seal for fire extinguishers



Nov. 3, 1953 c. K. HUTHSING PUMP BEARING SEAL FOR FIRE EXTINGUISHERS Filed Nov. 24, 1951 Horn ms INVENTOR. y CA/QRLESKM/TAG/NG B 1... m m u|l| K II I M@. 1 l d VVM Lwvv Patented Nov. 3, 1953 UNITED STATES PATENT OFFICE PUMP BEARING SEAL FOR FIRE EXTINGUISHERS Claims.

This invention relates to fire extinguishers and more specifically to a hand pump type extinguisher.

There are hand pump fire extinguishers in use today which include a pump rod or plunger which can be reciprocated by hand, the plunger having a portion lying within the extinguisher tank and having a pump valve assembly swingably carried thereby. The object of swinging the pump valve assembly is to cause said assembly to hang downwardly from the pump rod when the extinguisher is held in a more or less horizontal position or at an oblique angle, thereby permitting the pump valve inlet to lie in the liquid in the tank until substantially all the liquid has been ejected.

One difficulty with structures of this type has resulted from the inability to properly seal the pump discharge tube relative to the swinging valve assembly while at the same time insuring free swinging of the valve assembly. Another difliculty is that the pump assembly, being movable on the pump rod, has a tendency to vibrate or rattle.

It is, therefore, an object of the invention to provide a hand pump fire extinguisher having a swingable pump valve assembly suspended therefrom, together with means for eiiectively sealing the pump discharge tube relative to the swinging assembly.

Another object is to provide a specific type of seal ring and means for effectively holding the same in a sealing position and at the same time permitting free swinging of the pump assembly without permitting it to rattle.

Other objects and advantages will appear from the following description made in connection with the accompanying drawing wherein:

Fig. l is a longitudinal sectional view through an extinguisher embodying the invention;

Fig. 2 is an enlarged exploded view of the pump piston; and

Fig. 3 is an enlarged sectional view of the sealing structure adjacent the pump outlet.

The extinguisher includes a tank 4 having a main cylindrical shell 6, an upper end cap 8 and a lower end nozzle member ID. The end cap 8 has an aperture [2 which slidably receives a hollow pump rod or barrel It. A portion of the pump rod or barrel extends through the end cap aperture 12 and is secured to a cup-shaped element H3 which has a threaded nipple portion 18 which is secured into the shank 28] of a handle 22. The lower end of the shank 20 carries a cylindrical skirt 24 which is mounted upon a sleeve 26. The lower end of the sleeve 26 is provided with tail in Fig. 2.

an interrupted flange 28 which co-acts with an interrupted flange 30 to form a bayonet connection of conventional type. The cup-shaped element is has a shoulder 32 forming a lower seat for a compression spring 34 whose upper end bears against the underside of a flange 36 on the top of the sleeve 26. A sealing gasket 31 is interposed between the bottom of the shoulder 32 on the cup-shaped element 1 6 and the upper end of a sleeve 38 which defines the cap aperture l2 and is preferably formed integrally with the cap 8. When the bayonet connector portions 28 and so are disconnected, the pump rod or sleeve M can be reciprocated by suitable manipulation of the handle 22.

The underside of the tank end cap 8 is provided with a sleeve 40 having a shoulder 42 against which rests a seal ring 44. This ring closely yet slidably fits the outside of the pump rod or tube M. Beneath the seal ring 44 is a washer 46 which serves as the upper seat for a compression spring 48. This spring rests upon a shoulder 50 forming part of a sleeve 52. The lower end of the sleeve is shown reduced in diameter and extending into an apertured seal-retaining cup 54. In the cup 54 and beneath the lower end of the sleeve 52 is a diagonally split seal ring 56. Another and similar seal ring 58 is disposed in a counterbore formed in a casting 60 which forms part of a pump valve assembly. The casting 60 includes an apertured portion 62 which slidably receives the pump tube M with a loose fit. However, the seal rings 56 and 58 closely fit the pump tube I 4. These rings comprise flat split rings formed of a cellulose plastic. The plastic material permits the pump rod or tube M to slide relatively freely and the split seal ring has the quality of relatively closely gripping the pump tube is to form a seal without binding. It has been found that an efficient seal is produced when a ring such as the ring 56 is held rather tightly in position and also when a ring such as the ring 58 is permitted some freedom of axial movement. In either case, leakage of liquid along the pump rod is prevented.

Extending between the valve assembly casting 60 in the upper portion of the tank and a similar casting 64 in the lower portion of the tank is a cylinder 66 which is considerably greater in diameter than the pump rod or tube Id. The lower end of said pump rod or tube [4 has a sleeve 58 threaded thereon, said sleeve being shown in de- Intermediate the ends of the sleeve are pairs of liquid flow apertures 10. The sleeve 68 slidably passes through a piston 12 having packing I4 which closely fits the inner diameter of the cylinder 66. The lower end of the sleeve 68 is threaded and has a nut I6 thereon. The piston 12 is capable of sliding axially of the sleeve 68 between the nut I6 and a shoulder 18 on an upper portion of the sleeve. This exposes the uppermost or lowermost sleeve apertures I8 when the pump tube is reciprocated for purposes to be described below.

Extending through the pump rod or tube I4 is a liquid discharge tube 88. The lower end of this tube fits tightly in the nozzle I8 and its upper end passes through the cup-shaped element I8 and terminates in a bore 82 in the handle shank 29. A spring 84 is located in the bore 82 and presses downwardly on the end of the discharge tube 88 and upwardly on the handle 22. The discharge tube 88 extends through the lower valve assembly casting 64 with a loose fit. The casting 64 carries a washer 86 through which the discharge tube 88 also passes with a loose fit. Just below the washer 86 is a sealing washer 88 which is preferably of a cellulose plastic.

The sealing washer 88 is shown of smaller diameter than the washer 86 and it closely fits the discharge tube 88 so that when said sealing washer 88 is pressed against the larger washer 86 carried by the pump frame casting 64, a seal will be formed to prevent leakage between the main interior portion of the tank 4 and the interior of the pump frame casting 64.

Below the sealing washer 88 is an apertured disk 89 which comprises a spring seat against which the upper end of a compression spring 9| exerts an upward pressure as viewed in Fig. 1. The lower end of the spring 9| is seated on a flange 93 which forms a part of the outlet nozzle fitting I8 and which also serves to clamp the nozzle to the lower end of the extinguisher tank 4 where the nozzle passes through it. The spring 9| not only holds the washer 88 in sealing position but it yieldably holds the pump assembly against rattling.

As stated above, the sealing washer 88 is preferably made of a cellulose plastic but it should be understood that any smooth material can be used which will not be affected by the contents of the extinguisher and which has a low coemcient of friction.

It should also be noted that the spring seat 89 is held out of contact with the pump frame casting 64 and the larger washer 86 by the intermediate close fitting sealing washer 88. Thus, the entire pump assembly can swing freely about the discharge tube 88 without leakage at the point where the tube passes through the pump frame casting 64. This is particularly important in the lower portion of the extinguisher since it is frequently held with the nozzle I8 lower than the upper end of the extinguisher and the weight of the swinging pump assembly will be borne to a considerable degree by the sealing washer 8B.

Regardless of the position in which the extinguisher is held, the washer 88 will maintain a seal between the discharge tube 88 and the washer 86 because of the pressure of the spring 9I and its spring seat 89 against the washer 88. The spring 9I also serves as a cushioning device for resiliently supporting the swinging pump assembly which has a certain degree of longitudinal movement in the extinguisher tank 4.

The valve assembly, as stated above, has been previously used and is not a part of the present invention except as it relates to the location of the seal rings. However, a brief description of the valve parts is given for the purpose of a better general understanding of the device. The upper assembly 68 has a ball valve 98 which works against a seat 92 and a second ball valve 94 having a seat 96. There are identical ball valves 98 and I88 in the lower casting 64 having respective seats I82 and I84. The castings 68 and 64 are connected by a flow tube I88 and in the tube I86 is a distance bar I88. This bar permits the seating of only one of the balls 94 and I88 at a time.

When the bayonet joint elements 28 and 88 are disconnected and the pump tube I4 is reciprocated upwardly as viewed in Fig. 1, the packed pump piston 12 will assume the full line Position of that figure and liquid will be drawn from the main interior portion of the tank 4 through one or more ports II8 adjacent the ball valve I88. The liquid is then drawn through a passage H2 and past the ball valve 98 through a port II4 to the interior of the pump cylinder 66 beneath the piston I2. The suction created by the piston will close ball valves 98 and 94 on this upward stroke of the piston.

When the piston is pushed down, the pressure against the liquid beneath the piston will close the ball Valve 98 against its seat I82. It will also push the piston I2 up a short distance to the broken line position of Fig. 1. This will uncover the lower pair of liquid fiow apertures I8 in the sleeve 68 on the bottom of the pump tube I4 and the liquid will be forced upwardly in the tube I4 as indicated by arrows until it flows from the top of said tube through a passage H6 and into the top of the liquid discharge tube 88. This tube, of course, communicates with the nozzle I8 and the liquid is ejected from the nozzle.

When the piston I2 is pushed downwardly, a suction is created on the upper side of the piston and liquid is drawn upwardly through the tube I86 and past the ball valve 98 and thence into the upper end of the pump cylinder 66. When the piston is again pulled upwardly, liquid above said piston 12 is placed under pressure. This pushes the piston I2 down to the full line position thereof, permitting liquid to flow from the pump cylinder 66 through the upper pair of apertures 18 in the sleeve 88 on the bottom of the pum tube I4. This liquid passes upwardly in the pump tube and thence into the top of the discharge tube 88. It then fiows down through the discharge tube and out of the nozzle I8.

The split plastic seal rings 56 and 58 effectively seal the space between the pump tube I4 and the upper valve assembly casting 68 so that pressure is not lost. At the same time these split seal rings permit the entire valve assembly to swing freely about the pump tube I4 so that the valve assembly will hang down in the liquid in the tank when the tank is held generally horizontally. Obviously the tank can be held in any position of rotation and the valve assembly will still hang in a downward position.

It should be borne in mind that one of the principal features of the presentinvention is the lower sealing assembly comprising washers 86 and 88 and the spring 9I. In addition to the advantages pointed out above, this sealing assembly has another function. When the extinguisher has been used to the extent that liquid no longer lies about the washers 86 and 88, there is a tendency for the pump to pump air from the empty portion of the tank through the pump frame casting 64 past the discharge tube 88. With the washers and the spring 9| as described above, a tight seal is effected which will prevent this and permit pumping of practically all of the liquid from the interior of the tank. At the same time, the small sealing washer 88 with its minimum of frictional contact with the washer 86, will provide a bearing contact having a minimum of frictional resistance to swinging of the pump assembly.

It will, of course, be understood that various changes in the form and details can be made without departing from the spirit of the invention.

Iclaim:

1. In a hand pump fire extinguisher, a tank, a pump assembly in the tank including a. discharge tube having an outlet end with a nozzle fitting into which the tube extends, a pump frame in the tank swingable about said discharge tube, a washer carried by said pump frame and loosely fitting said discharge tube, a friction reducing sealing washer closely fitting said discharge tube and engaging a face of said first mentioned washer, and a compression spring interposed between the nozzle fitting and the friction reducing sealing washer to hold the sealing washer against the first mentioned washer and also to hold the pump frame against rattling.

2. The structure in claim 1, and a spring seat between the spring and the sealing washer, said spring seat comprising an apertured disk loosely fitting about the discharge tube and held out of engagement with the pump frame and said first mentioned washer by said sealing washer.

3. The structure in claim 2, and the sealin washer being of less diameter than the first mentioned washer to limit surface contact between the washers.

4. In a hand pump fire extinguisher, a tank, a pump rod slidable in the tank and having a handle portion lying outside of the tank, a pump valve assembly mounted on the rod and swingable thereabout through the medium of a bearing lying loosely about the rod, a split seal ring about the rod and having 'a face engaging the bearing, and a retainer about the rod and engaging the opposite face of the seal ring.

5. In a hand pump fire extinguisher, a tank, a pump rod slidable in the tank and having a handle portion lying outside of the tank, the tank including structure in its interior through which the pump rod is loosely slidable and portions of it constitute an abutment face lying about the pump rod and facing axially of the pump rod, a seal ring lying closely about the pump rod in slidable relation thereto, said seal ring being disposed against said abutment face, and a spring device having one end bearing against said relatively stationary structure and its other end bearing against said seal ring to l yieldably urge the seal ring against the abutment surface.

CHARLES K. HU'I'HSING.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,688,195 MacGregor Oct. 16, 1928 2,116,319 Miller May 3, 1938 2,326,861 Huths1ng Aug. 1'1, 1943 

